I definitely agree with and vote for many, if not all, of the above mentioned features. Coming from the perspective of merchant as well as customer, I'm first led to hope for:
1. Some way to designate demos differently. I'm not going to pretend to know the dynamics behind setting something like that up, but it'd be much nicer if there was a way to let folks be able to search the MP and filter via price but not be faced with a gazillion demos that they weren't expecting OR at least an easier way to upload the demos in addition to the actual items so there's a nicer view/easier search.
2. For sure would love to see an editable field for store policies so you don't have to paste them in every description, they'll just be part of the listing automatically but can be updated as necessary. Sure there's a policy section on the storefront but many do not look at this and it doesn't offer enough space for an accurate and full policy section. To add to this, also if something changes it should update on every listing as opposed to having to go in and edit each individual item listed. Maybe during the listing setup a radio button could give the option to include policies on the listing and that way one policy section can be used and linked to both places?
3. A built in redelivery system for copy items would be fabulous. We already have the option to select whether something is CMT, etc. it could be tied to that in some way. If a copy item is chosen, it automatically gets placed in a redelivery list that can be on the store front page or even as another option if someone has already purchased it instead of 'Add to Cart', 'Buy As Gift', another button 'Redeliver Previously Purchased'. Idk if that's possible to really code or whatever but you get the idea.
4. Easier updating for prices on the 'manage listing' page instead of editing each individual listing for sure. If something's been sitting for a while and I want it to go, and maybe I have many items like this, I don't want to take forever updating. It'd be nice to edit them all at once from one page.